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<html lang="zh-CN">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <b>加粗</b>
  <i>倾斜</i>
  <u>下划线</u>
  <s>删除线</s>

  <br>

  <!-- 推荐使用 -->
  <strong>加粗</strong>
  <em>倾斜</em>
  <ins>下划线</ins>
  <del>删除线</del>
</body>

</html>